The present invention relates to hinges for an opening door or window frame, of the type comprising one first and at least one second knuckle part each provided with a leaf for fixing it to the movable frame and to the fixed frame respectively of the door or window; a pin which connects the first and second knuckle parts together such that they can rotate; and means allowing adjustments to be made between the first and second knuckle parts.
Hinges of this type are currently used in a multitude of applications, including on relatively heavy doors in which the frames consist of metal sections. In these applications, adjustment between the first and the second knuckle parts of the hinges on the door frame, in other words between the movable frame and the fixed frame, is usually possible both in a direction parallel to and in a direction perpendicular to the general plane of the door, advantageously independently of each other.
Adjustment perpendicular to the general plane of the door in particular serves to adjust the compression force on the seal, which is usually provided on one of the two frames, so as to give the optimum compression value to ensure a seal against external agents. Adjustment in a direction parallel to the general plane of the door, on the other hand, serves to adjust the gap between the movable frame and the frame proper.
Italian Utility Model Application No. TO97U000055 in the name of the present Applicant discloses a hinge for an opening door or window frame of the type defined above, in which the means allowing adjustment between the first and second knuckle parts perpendicular to the general plane of the door or window include a sleeve which is inserted into the second knuckle part such that it can be oriented angularly and which has an eccentric cylindrical cavity into which the pin is inserted. The sleeve and the second knuckle part have mutual keying means designed to allow stable orientation of the sleeve in a plurality of different relative angular positions.
This adjustment system has the advantage of allowing particularly practical, easy and rapid adjustment between the movable frame and the fixed frame of the door or window, perpendicularly to the latter""s general plane.
The present invention constitutes an improvement to the subject-matter of the abovementioned Italian Utility Model Application No. TO97U000055 and, more specifically, its object is to make the hinge self-centring, especially with regard to the axial alignment between the pin and the second knuckle part, so as to eliminate any negative effects that may arise due to play introduced during construction or assembly between these components of the hinge.
According to the invention this object is achieved by a hinge for an opening door or window frame of the type defined at the outset which is principally characterized in that, in accordance with Claim 1, the abovementioned sleeve and the pin of the hinge have surfaces that come into mutual axial contact and are spherical in shape.
In a preferred embodiment of the invention the sleeve has a bottom wall which closes off its cavity, this bottom wall and the end of the pin that faces it both having an essentially hemispherical and mutually complementary shape.
If means for adjusting the height of the first knuckle part relative to the second knuckle part are also provided, and include a lower support for the said sleeve engaged inside the second knuckle part such that it can move axially, the invention will also envisage the said support and the said sleeve having surfaces that come into mutual axial contact and are spherical in shape.
In this way three spherical surfaces are defined which will ensure a perfect self-centring action between the pin, which is integral with the first knuckle part of the hinge, and the adjustment unit associated with the second knuckle part.